A model of twin growth in magnesium is presented together with the analysis of defects responsible for this growth. The twin interface is represented by {10-12} and basal-prismatic facets. Disclinations are situated in the facet junctions creating dipoles superimposed on basal-prismatic and conjugate twin facets. The migration of facets is mediated by the conservative motion of interfacial disconnections. The {10-12} interfaces contain b2/2 twinning disconnections. The facet junctions serve as sources and sinks for these defects. Two types of disconnections (bbp1/1 and bbp2/2) were observed in basal-prismatic boundary. The dipoles of bbp1/1 disconnections were nucleated in the vicinity of existing defects of this type. Interaction of this dipole with existing bbp1/1 leads to the creation of a bbp2/2 disconnection, which is later absorbed in the facet junction. The nucleation of bbp2/2 dipoles was not observed. In twin embryo growth, the basal-prismatic segments remain coherent with a fixed length,while the twin segments grow indefinitely
Trvalý link: http://hdl.handle.net/11104/0236497